Generally you should have a separate transmission cooler (with
automatic),
I can add this, price do it yourself $60-80. I plan to do this.
why? "heavy duty battery and alternator"

Suspension might be a problem although this particular year comes with
quote "heavier" leaf springs.

The V6 is a 3.8 litre (3800) GM motor (170hp). I will be towing this
boat short distances ( less than 1/4 mile) except twice a year, when I
will tow it approx 150 miles. The boat and trailer should be around
3000lbs, curb weight of the car 3400lbs.What do you think?